Buoyancy material with composite sandwich damping structure and preparation technology of material

The invention relates to a buoyancy material with a composite sandwich damping structure. The buoyancy material comprises a core material, a plane materiel and a damping coating, wherein the core material is a buoyancy material module; the buoyancy material module comprise epoxy resin, an epoxy reactive diluent, a curing agent, a silane coupling agent and hollow glass beads. The solid buoyancy material module is formed by the processes of premixing, kneading, mould pressing, curing and cutting into solids; the plane material is high-rigidity fiber-enhanced epoxy glass steel, sheet steel or an aluminium alloy plate; the damping coating is a polyether urethane elastomer which is coated between the core material and the core material, between the core material and the plane material, and between the plane material and the plane material. By adopting the buoyancy material disclosed by the invention, the traditional buoyancy material has higher waterproof sealing property and damping property, so that the solid buoyancy material is wider in application range.